Obscured by Clouds. The rough and ready blog of a cloud benighted biologist and amateur astronomer. Astroblog will cover my interests in astronomy, biology and Life, the Universe and Everything.

Friday, February 12, 2010

The Opposition of Mars from Other Planets

By now you have learnt that when a planet is in opposition with Earth, Earth lies directly between it and the Sun. Now what if we were standing on a planet inside the orbit of Earth, would we see Earth and Mars bright and close together?

The answer is a qualified yes, if the planet itself is nearly in a straight line betwen the Sun, Earth and Mars.

When Mars and the Earth were aligned, Venus was pretty much in a straight line with them and the Sun as well. Unfortunately, Venus was on the other side of the Sun, so Mars and Earth were invisible in the Suns glare on the night of the opposition (Not that you could have seen it anyway as the surface of Venus is shrouded in dense clouds of Sulphuric acid).

On the next opposition, 2012, Venus is well to the side of Earth and Mars, so they don't line up at opposition.

Mercury was a bit better off this opposition, it was off to the side, so Mars and Earth didn't align as seen from Mercury on the night of the Opposition, but some time later.

The top image is Earth and Mars as seen from Venus (if you could actually see through the atmosphere, that is) on February 2, when Earth and Mars pull away from the Sun. Th lower image is Earth and Mars on the 14th of February as seen from night-side Mercury. The close pair would be quite spectacular, and are in an interesting bit of sky (should have turned the atmosphere off for that oe though).

Both images are rendered in Stellarium 0.10.2, which allows to to image the sky from other planets.